Strange 'rumbling'

[thatfatbloke]

On the way to work this morning the old 300TE started to make a sort of rumbling noise from the offside under the bonnet. This was only apparent when idling at traffic lights etc. It went away when driven. I stopped at a garage to get baccy,and noticed that it even did it with just the ignition on and the engine not running. It got me to work no problem. All gauges reading normal and drove normally. On the way home it did it again a couple of times. I have let it cool down a bit and checked the water level which is fine,and of course,you guessed it,nothing!!. I know noises can be difficult to describe,but the only time I've heard this sort of noise before was when there was an air lock in the cooling system of a car I had years ago,but that only happened after switching the engine off after a run. Would the temperature gauge stay in the normal zone if there was an airlock,and would the water level stay 'normal'?.

 

[brandwooddixon]

If the rumbling occurs when the ignition is on but the engine not running, does it go away when you turn the engine off?

Is you car fitted with an electric fan? I had a car in the past where the electric fan bearing went and it created a heck of a racket when running. Got me through the Slovakian/Austrian border extra quick and without checks!

 

[Doug1234]

Could it be the electric coolant pump ?

 

[thatfatbloke]

Here's the little wriggler that's making all the row. It's located just under the washer bottle and seems to be connected to the accelerator. What is it please? How much?. Easy to replace?. Safe to keep using until I can find one?. Thanks.

 

[thatfatbloke]

Any ideas?. Can't find it in the Haynes manual.

 

[star]

Looks like a cruise control actuator.

 

[thatfatbloke]

Thanks for that 'Star'. I'll have a fiddle with the cruise control stalk in the morning to see if I can get it to shut up!!.

 

[thatfatbloke]

All quiet on the western front!!. It made a row first thing this morning,stopped at Tesco's for petrol,and since restarting has been as quiet as a mouse. Weird. I'll leave it be for now.

 

[bigtwin]

Every little helps.

 

[thatfatbloke]

Another quiet day. I personally think the noise was an air lock in the cooling system. When I started her this morning there was a brief 'gurgling' noise like water running,coming from behind the heater controls. There is a pipe coming from the bottom of the expansion tank which runs next to the cruise control actuator on it's way to wherever it's going,which made it seem as if the noise was coming from the actuator. Heater working,temperature gauge normal,water level fine. That's good enough for me!. Thanks for your replies.